Screw-in heat exchanging element for water heaters

ABSTRACT

A screw-in heat exchanger which is adapted to a dedicated heating element receptacle, commonly found on domestic electric hot water heater tanks, which allows a tank&#39;s water to be heated or cooled while circulating a hot or cold heat transfer fluid through the heat exchanger.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of provisional patent application Ser. No. 61/832,137, filed 2013 Jun. 6 by the present inventor.

BACKGROUND

1. Prior Art

The following is a tabulation of some prior art that presently appears relevant:

U.S. Patents Pat. No. Kind Code Issue Date Patentee 6,837,303 B2 Jan. 4, 2005 Butler 4,865,005 Sep. 12, 1989 Griffith 4,926,830 May 22, 1990 McNelley 1,849,175 A Mar. 15, 1932 Grant

U.S. Patent Application Publications Publication Nr. Kind Code Publ. Date Applicant 2003/0159804 A1 Jan. 4, 2005 Butler

2. Background of Invention

Potable domestic water may be heated various ways. Energy costs also vary depending on the heating method used. The energy cost of heating water using a standard electrical heating element may be relatively high compared to other means of heating water such as using solar, heat pump, or gas-fired technologies. Solar water heating may be viewed as a cost effective method by collecting the sun's radiant energy to heat water either directly or indirectly using active or passive solar water heating systems. Gas fired and heat pump technologies currently provide a relatively lower energy cost of heating water compared to using standard electrical heating elements to heat water.

In active solar water heating systems, a pump is used to circulate heat transfer fluid from a storage tank through a solar collector, such as a series of tubes within a box with a transparent cover. Typically, the pump is controlled by a control system which activates the pump when the temperature in the solar collector is higher than the temperature in the storage tank. Once the heat transfer fluid has been heated, it then passes through a heat exchanger or series of heat exchangers which exchange heat between the heat transfer fluid and the water to be heated. Although active systems provide better control than other systems, control systems and pumps may be expensive and require additional energy to operate.

Passive, thermo-siphon, and batch solar water heating systems are beyond the scope of this document as existing technologies do not utilize heat exchangers that are similar in fashion to implementations herein.

Hybrid heat-pump water heaters may indirectly and efficiently heat water using a system of condensers, evaporators, pumps, heating elements, and heat exchangers, currently saving up to 60% of the cost of heating the water compared to using just a standard electrical heating element. Implementations herein may be combined with heat pump technologies in order to heat water.

Standard electrical heating elements create heat as a byproduct of electrical resistance in a simple electrical circuit. When enough electricity passes through a wire with some amount of resistance, heat is created as a byproduct and thereby transferred to a fluid such as water inside of a water heater tank when the fluid comes into direct contact with the electrical heating element. A typical 40 or 50 gallon household electric water heater usually has 2 standard electrical heating elements which screw into dedicated heating element receptacles, one receptacle located closer to the top of the tank, and one closer to the bottom. The heating element(s) usually work in conjunction with electronic thermostats that regulate when the heating element electrical circuit is open or closed.

Gas-Fired water heating is a relatively simple process where combustible fluids or gases are ignited to create heat as a byproduct, where the heat may be channeled through a heat exchanger or heat exchanging mechanism that comes into direct contact with the water to be heated. Recently, the use of natural gas as an inexpensive source of heating water has been widely accepted in locations that have ready access to natural gas.

Many previously mentioned water heating systems are either relatively expensive or require extensive installation procedures which drive up the cost of the systems to surpass the real or perceived benefit gained from implementing such systems. In their current configuration, existing water heating systems may lack consumer buy-in without a dramatic reduction in cost or ease of installation.

One of the many objectives of implementations related to a screw-in heat exchanging element for water heaters may be to improve existing water heating systems by creating, in some embodiments, a low cost heating element replacement which acts as a heat exchanger and makes up part of a water heating system; the heat exchanging element may in some embodiments be retrofitted to a water heater that uses standard electrical heating elements and may prove to be a value-added component of many water heating systems due to the implementation's low cost, versatility, ease of installation, and maintenance capabilities.

SUMMARY OF INVENTION

Implementations generally relate to improvements for water heating systems, and more particularly, to a screw-in heat exchanging element for water heaters, adapted to a water tank's dedicated heating element receptacle.

Advantages of Invention

Implementations of screw-in heat exchanging element for water heaters like those disclosed in this document may have one or more or all of the following advantages, as well as other benefits discussed elsewhere in this document.

-   -   Screw-in heat exchanging element for water heaters         implementations provide a viable retrofit installation option         that minimizes the cost of changing from a standard electrical         water heating system to a solar, heat pump, or other water         heating technology, and allows for the screw-in heat exchanging         element for water heaters to be easily removed for various         purposes such as maintenance, repair or replacement.     -   In addition to retrofit installations, screw-in heat exchanging         element for water heaters implementations provide a standardized         option for new and used hot water tanks, resulting in lower         costs, less materials used, and streamlined repairs or         installations.     -   Screw-in heat exchanging element for water heaters         implementations provide a benefit in that they allow you to         integrate low pressure solar collectors as part of a water         heating system. Low pressure solar collectors are usually much         less expensive than high pressure ones because the low pressure         collectors are often constructed out of thin thermoplastics         without any protective casing.     -   Screw-in heat exchanging element for water heaters         implementations provide a remedy against hard water scaling,         which commonly builds up on heat exchangers and heating         elements, by providing the ability to periodically remove the         heat exchanging element from a tank and clean off the hard water         scale, thereby maintaining the efficiency of the heat exchanging         element.

DRAWINGS—FIGURES

FIG. 1 is a perspective view of a screw-in heat exchanging element and shows various external aspects in accordance with one embodiment.

FIG. 2 is a disassembled view of a screw-in heat exchanging element which diagrams both internal and external aspects in accordance with one embodiment.

FIG. 3 is a cutaway view of an electric hot water heater where all standard electric heating elements have been replaced with screw-in heat exchanging elements in accordance with one embodiment.

FIG. 4 is a cutaway view of an electric hot water heater where a lower standard electric heating element has been replaced with a screw-in heat exchanging element in accordance with one embodiment.

DRAWINGS - REFERENCE NUMERALS 1 Inlet 2 Male threaded mounting base 3 Internal tube 4 Capped end 5 External tube 6 Internal coil 7 Outlet 8 Plumbing fittings 9 Removeable insert 10 External coil 11 Insertable external portion 12 Anode rod 13 Cold water inlet 14 Electrical conduit 15 Hot water outlet 16 Potable water 17 Tank drain valve 18 Heating element receptacle 19 Tank exterior 20 Tank wall 21 Tank insulation 22 Heat Exchanging Element 23 Electric Heating Element

DETAILED DESCRIPTION OF ONE EMBODIMENT

This document features a screw-in heat exchanging element for water heaters designed to take the place of one or more standard electric heating elements found on water heating tanks. There are many features of screw-in heat exchanging element for water heaters implementations disclosed herein, of which one, a plurality, or all features or steps may be used in any particular implementation.

In the following description, reference is made to the accompanying pictures which form a part hereof, and which show by way of illustration possible implementations. It is to be understood that other implementations may be utilized, and structural, as well as procedural, changes may be made without departing from the scope of this document. As a matter of convenience, various components will be described using exemplary materials, sizes, shapes, dimensions, and the like. However, this document is not limited to the stated examples and other configurations are possible and within the teachings of the present disclosure.

One embodiment of a screw-in heat exchanging element is illustrated in FIG. 1 and consists of an external tube (5) made of thermally conductive material that is capped on one end (4) and has standard plumbing fittings (8) consisting of an inlet (1) and an outlet (7) which define an internal flow path for heat exchange fluid, all of which make part of either an insertable external portion (11) or a removeable insert (9). When the heat exchanging element is inserted into a domestic hot water tank by way of a male threaded mounting base (2) and has heated fluid pumped through it, thermal energy is transferred between the insertable external portion and potable water (16) within a tank. An external coil (10) is added to or formed as a part of the external tube to increase the surface area of the thermally conductive material. The external coil may also increase fluid turbulance through convection which aids in thermal conduction between the heated fluid and the potable water.

FIG. 2 illustrates a dissasembled view of a screw-in heat exchanging element where it is made evident that the heat exchanging element consists of an insertable external portion (11) and a removeable insert (9). The inlet (1) and outlet (7) are part of the removeable insert and attached to an internal tube (3) which transfers the heated fluid to an opening near the closed end of the external tube (5). The heated fluid then travels back between the walls of the external tube and the internal tube through a spiral channel created by an internal coil (6). The internal coil is added to the inside of the external tube to increase the internal surface area of the thermally conductive material and to create additional fluid turbulance during operation.

FIG. 3. illustrates a cross-sectional view of an electric domestic hot water heater tank with screw-in heat exchanging elements replacing both standard electric heating elements. An electric domestic hot water heater tank in this example consists of an tank wall (20), tank insulation (21), tank exterior (19), a cold water inlet (13) and a hot water outlet (15), tank drain valve (17), electrical conduit (14), anode rod (12), and heating element receptacles (18). During operation, heated fluid is pumped through the heat exchanging elements (22) and transfers heat directly into the potable water supply (16) of the electric water tank.

FIG. 4. illustrates a cross-sectional view of an electric domestic hot water heater tank with a screw-in heat exchanging element replacing a lower standard electric heating element. An electric domestic hot water heater tank in this example consists of an tank wall (20), tank insulation (21), tank exterior (19), a cold water inlet (13) and a hot water outlet (15), tank drain valve (17), a standard electrical heating element (23), electrical conduit (14), anode rod (12), and heating element receptacles (18). During operation, heated fluid is pumped through the heat exchanging element (22) and heat is transferred directly into the potable water supply (16) of the electric water tank while leaving the upper standard electrical heating element in tact which acts as an additional source of heat.

Structure of Invention

In general, a screw-in heat exchanging element for water heaters may include a single or double wall, screw-in heat exchanging element for electric water heaters, comprised of internal and external tubular element(s); the external tubular element may be linear, closed on one end, and contain formed passageways between the walls of the internal and external tubular elements for the transfer of heat exchange fluid, and may contain thermally conductive material fastened to or formed as part of the inside and outside of the external tubular element to increase the surface area of the heat exchanging element that comes into direct contact with the water or fluid to be heated; an internal coil may be located between the internal and external tubular elements, forming a spiral internal passageway for the heat transfer fluid. An inlet and an outlet with related fittings defining a flow path for heat exchange fluid; a mounting base on which the external tubular element is mounted; the mounting base may have a male threaded portion adapted to screw into a dedicated heating element receptacle provided on a standard electric water heater tank, to allow the flow of heat transfer fluid through the heat exchanging element from an outside heat source when the heat exchanging element is connected thereto; the mounting base may contain a hexagonal shape therein for the purpose of screwing into a heating element receptacle.

Many implementations of a screw-in heat exchanging element for water heaters and its related components are possible.

SPECIFICATIONS, MATERIALS, MANUFACTURE, AND ASSEMBLY OF INVENTION

It will be understood that implementations are not limited to the specific components disclosed herein, as virtually any components consistent with the intended operation of a screw-in heat exchanging element for water heaters implementation may be utilized. Accordingly, for example, although particular components and so forth, are disclosed, such components may comprise any shape, size, style, type, model, version, class, grade, measurement, concentration, material, weight, quantity, and/or the like consistent with the intended operation of a water heat exchanger. Implementations are not limited to uses of any specific components, provided that the components selected are consistent with the intended operation of a screw-in heat exchanging element for water heaters.

Accordingly, the components defining any screw-in heat exchanging element for water heaters implementation may be formed of any of many different types of materials or combinations thereof that can readily be formed into shaped objects provided that the components selected are consistent with the intended operation of a heat exchanging element implementation. For example, the components may be formed of: rubbers (synthetic and/or natural) and/or other like materials; glasses (such as fiberglass), carbon-fiber, aramid-fiber, any combination thereof, and/or other like materials; polymers such as thermoplastics (such as ABS, CPVC, Fluoropolymers, Polyacetal, Polyamide; Polycarbonate, Polyethylene, Polysulfone, PVC, and/or the like), thermosets (such as Epoxy, Phenolic Resin, Polyimide, Polyurethane, Silicone, and/or the like), any combination thereof, and/or other like materials; composites, and/or other like materials; metals and metal plating, such as zinc, chrome, magnesium, titanium, copper, iron, steel, carbon steel, alloy steel, tool steel, stainless steel, galvanized steel, spring steel, aluminum, gold, platinum, beryllium, any combination thereof, and/or other like materials; alloys, such as aluminum alloy, titanium alloy, magnesium alloy, copper alloy, any combination thereof, and/or other like materials; any other suitable material; and/or any combination thereof.

For the exemplary purposes of this disclosure, the various screw-in heat exchanging element for water heaters implementations may be formed of a metal or alloy such as copper, aluminum, steel, galvanized steel or stainless steel and may include a polymer such as chlorinated polyvinylchloride (CPVC). A plurality of plumbing, mounting and fastening configurations which vary in dimension may be employed, such as plumbing fittings, thread sealants, unions, dielectric unions, pipes, tubes, wires, gaskets, flanges, glues, epoxies, silicon, polytetrafluoroethylene (PTFE) tape, rivets, hex nuts, rubber washers, lock washers, couplings, nipples, O-rings and the like.

Various screw-in heat exchanging element for water heaters implementations may be manufactured using conventional procedures as added to and improved upon through the procedures described here. Some components defining screw-in heat exchanging element for water heaters implementations may be manufactured simultaneously and integrally joined with one another, while other components may be purchased pre-manufactured or manufactured separately and then assembled with the integral components.

Manufacture of these components separately or simultaneously may involve extrusion, pultrusion, vacuum forming, injection molding, blow molding, resin transfer molding, casting, stamping, cutting, bending, hardening, punching, drilling, machining, threading, soldering, brazing, welding, and/or the like. If any of the components are manufactured separately, they may then be coupled with one another in any manner, such as with a threaded union, a fitted union, an adhesive, a sealant, a solder, a weld, a fastener, or any combination thereof, and/or the like for example, depending on, among other considerations, the particular material forming the components.

It will be understood that the assembly of screw-in heat exchanging element for water heaters implementations are not limited to the specific order of steps as disclosed in this document. Any steps or sequence of steps of the assembly of screw-in heat exchanging element for water heaters implementations indicated herein are given as examples of possible steps or sequence of steps and not as limitations, since various assembly processes and sequences of steps may be used to assemble screw-in heat exchanging elements for water heaters implementations.

Implementations of screw-in heat exchanging elements for water heaters are particularly useful for retrofitting electric hot water tanks into solar and heat pump water heating tanks. However, implementations are not limited to uses relating to electric water heaters only. Rather, any description or photograph relating to electric water heaters is for the exemplary purposes of this disclosure, and implementations may also be used in a variety of applications with similar results. For example, screw-in heat exchanging element for water heaters implementations may be used to mount heat exchangers inside of tanks which may heat or cool other fluids of virtually any type.

In places where the description above refers to particular implementations, it should be readily apparent that a number of modifications may be made without departing from the spirit thereof and that these implementations may be alternatively applied. The presently disclosed implementations are, therefore, to be considered in all respects as illustrative and not restrictive. 

1. An insertable in-tank heat exchanging element comprised of a heat exchanger having a tubular element, an inlet, and an outlet defining a flow path for heat exchange fluid; adapted to screw into a dedicated heating element receptacle located on a fluid heating tank.
 2. An heat exchanger comprising: a tubular element; an inlet; an outlet defining a flow path for heat exchange fluid; wherein the heat exchanger is adapted to insert into a fluid tank's dedicated, heating element receptacle.
 3. The heat exchanger of claim 2 wherein the heat exchanger is screwed into a dedicated, heating element receptacle located on a fluid tank.
 4. A fluid tank comprising: A tank for holding fluid; A plurality of dedicated, heating element receptacles; An electric heating element; A heat exchanger comprising: a tubular element; an inlet; an outlet defining a flow path for heat exchange fluid; wherein the electric heating element and the heat exchanger are inserted into said receptacles.
 5. The fluid tank of claim 4 wherein the plurality of dedicated, heat exchanger receptacles further comprise a lower and a higher receptacle with respect to the longitudal axis of the tank.
 6. An heat exchanger comprising: a tubular element; an inlet; an outlet defining a flow path for heat exchange fluid; wherein the heat exchanger is adapted to screw into a fluid tank's dedicated, heating element receptacle. 